Spectacular progress in the development of light emitting diodes, LEDs, has made LED-based lamps to compete with incandescent lamps, and within short a large part of the incandescent lamps will be replaced by retrofit LED lamps (not in the least due to legislation). LEDs offer several advantages over traditional light sources, such as long lifetime, high lumen efficacy, low operating voltage, small form factor (giving design flexibility), almost pure spectral colors, fast modulation of lumen output, and instant on.
In general, incandescent lamps as well as LED lamps are used in a mode in which they are either full-on or off. Retrofit LED lamps can be made to be dimmable by standard dimmer switches arranged for instance on a wall. However, in practice, only few lamps are connected to a dimmer switch in the home. Replacing ordinary switches by dimmer switches implies an effort in time and cost only few households are anticipated to make.
At the same time, there is a trend towards personalization of lighting. The problem is therefore that, despite this need for personalization of lighting, the present infrastructure allows only switching lamps on and off. Thus there is a need for providing an alternative manner of controlling the lighting settings of LED based lamps.